The present invention relates to a multidimensional liquid chromatography device including a plurality of separating columns.
In recent years, on a field of proteomics for analyzing exhaustively behaviors of all of various proteins appearing in living bodies, mass spectrographs have been mainly used. The multidimensional liquid chromatography device extracts the various proteins from a specimen obtainable from the living body to be treated by the mass spectrograph.
In the multidimensional liquid chromatography device, columns of respective extracting principles different from each other are connected in series to extract various components from the specimen of the living body. In the multidimensional liquid chromatography device, an eluting solvent used for the extraction in the first column is generally different from an eluting solvent used for the extraction in the second column. On the field of proteomics, an extracting column such as a cation exchanger column or the like in which an electrolytic solution including salt is used as the eluting solvent is used as the first column. Since such solution affects the measurement of the mass spectrograph, an analyzing method is arranged so that a specimen eluted in the first extracting column is temporarily stored in a storing column, and thereafter a flow path switching valve is operated to supply a solution applicable to the mass spectrograph other than the electrolytic solution from the storing column to the second column, whereby the specimen is supplied to the mass spectrograph while the electrolytic solution is prevented from being introduced into the mass spectrograph.
A device including two storing columns (enrichment columns) for storing components of the specimen extracted in the first extracting column (SCX column) at first stage and a flow path switching valve (Micro 10-port valve) for switching the connection between the two storing columns is disclosed by the publication on pages 134-143 by E. Nagele et al. of “Journal of Biomolecular Techniques” of Volume 15, 2004. In this device, the specimen is injected to collect required components of the specimen in the first extracting column, and salt whose concentration is changed is periodically injected into the first extracting column to elute the components of the specimen collected in the first extracting column. The components of the specimen eluted in accordance with the injected salt are stored alternately in the two storing columns. The component of the specimen stored in the storing column connected to the second extracting column (C18 RP column) at second stage through the flow path switching valve is pressed by Nanoflow pump to pass through the second extracting column, and subsequently analyzed.
That is, in the device of the publication, one of the storing columns is connected to the first extracting column to store the component of the specimen eluted from the first extracting column, while the other one of the storing columns is connected to the second extracting column and the Nanoflow pump to elute the component of the specimen from the second extracting column, so that the elution of the component of the specimen from the first eluting column caused by supplying salt can be performed periodically without being stopped.